Point-of-Care medical in vitro diagnostic (IVD) tests are defined as diagnostic tests realized at the time of care with biological samples outside of their normal environment. Applications include quantification of the presence of biomolecules in a fluid sample solution. A majority of the current point-of-care IVD tests are intended for medical applications. In the scope of this invention, capsule systems are used to handle the patient fluid sample, to treat it and to transfer it to nanofluidic biosensors for quantification of the presence of biomolecules in the solution.
Nanofluidic biosensors are defined as fluidic systems with nanometer-sized confinements and/or lateral apertures.
Several patent applications such as Swiss patent application CH 01824/09, PCT application IB2010/050867, PCT application IB2012/050527 and PCT application IB2013/060935 discloses nanofluidic biosensors with lateral apertures for the detection of biomolecular interactions. They also disclose their use with optical systems, the method to decrease the incubation time and to increase the sensitivity of the described biosensors.
Current practices for the detection of specific biomolecules can be divided in two categories: (a) the labeled techniques and (b) the label-free techniques.
Among the labeled techniques, the widely used are fluorescence, colorimetry, radioactivity, phosphorescence, bioluminescence and chemiluminescence. Functionalized magnetic beads can also be considered as labeling techniques. Labeled techniques advantages are the sensitivity in comparison to label-free methods and the molecular recognition due to specific labeling.
Among the label-free techniques, the widely used are electrochemical biosensors, referring to amperometric, capacitive, conductometric or impedimetric sensors, which have the advantage of being rapid and inexpensive. They measure the change in electrical properties of electrode structures as biomolecules become entrapped or immobilized onto or near the electrode, but all these concepts lack molecular specific contrast, sensitivity and reliability.
Enzyme linked immunosorbent assay (ELISA) is an important biochemical technique mainly used to detect the presence of soluble biomolecules in serum, and thus is widely used as diagnostic tool in medicine and quality control check in various industries. ELISA analysis are however expensive, require relatively large amounts of solution and are time consuming.
The other important technologies for biomolecular diagnostics are Western and Northern blots, protein electrophoresis and polymerase chain reaction (PCR). However, these methods require highly concentrated analytes and do not allow high throughput samples testing.
Objectives
It is an object of this invention to improve usability of rapid quantitative diagnostic tests.
Still another object of the invention is to directly assess a fluid sample containing big components which have to be extracted from the fluid before the measurement.
Still another object of the invention is to enhance the identification of the capsule.